As an electrophotographic image forming apparatus, there is known a printer provided with an apparatus body and a process cartridge removably mounted in the apparatus body.
As an example of such a printer, Japanese Patent Application Publication No. 2004-224507 has proposed a printer, in which the apparatus body is formed with an opening for introducing sheets such as recording papers and in which the process cartridge accommodates toner and supports a photosensitive drum.
In the printer having the above-described configuration, during an image forming process, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum, and toner is supplied to the electrostatic latent image, whereby a visible image (developer image) is carried on the peripheral surface of the photosensitive drum.